Data storage devices store digital information on a disc or storage media. Heads read data from or write data to the data storage disc. Heads include transducer elements, such inductive, magneto-resistive and magneto-optical transducer elements for read-write operations. Heads are coupled to an actuator assembly via a head suspension assembly and the actuator assembly is energized to position the heads relative to selected data tracks for read-write operations. The head suspension assembly includes a load beam which supplies a load force to the head at a load or gimbal point. The head is coupled to the suspension assembly or load beam through a gimbal spring so that the head pitches and rolls relative to the load or gimbal point to follow the contour of the disc or data storage surface.
Transducer elements of the head are carried on a trailing edge of an air bearing slider for proximity, near proximity or near contact recording. The air bearing slider includes at least one raised bearing surface and at least one recessed bearing surface. Rotation of the disc or storage medium provides an air flow along the air bearing surface of the slider to provide a hydrodynamic lifting force which is countered by the load force to define in part a fly height for the slider for read-write operations. Head-disc spacing or fly height is controlled in part by air bearing pressurization, where as the fly height decreases, air bearing pressure increases and air bearing pressure decreases as the fly height increases to provide a relatively stable fly height. Areal disc drive density is increasing requiring lower fly heights or head-disc spacing between the transducer elements at the trailing edge of the slider (or pole tip fly height (PTFH)) and the disc surface for desired read-write resolution and clarity. The lower fly heights demand better control over pressurization of the air bearing surfaces.
Variations in the relative linear velocity of the rotating disc between the inner and outer diameters of the disc and variations in the skew angle between the head and disc relative to the inner and outer diameters of the disc can affect air bearing pressurization or fly height of the slider based upon radial position of the head. Heads are fabricated by a wafer fabrication process which can introduce a cross curve between opposed sides, along a cross dimension or width, of the slider or head. The cross curve can affect pressurization or the pressure profile of independent bearing surfaces across the cross dimension or width of the head or slider. Embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.